[VOIPSEC] RE: TLS as the SIP security mechanism

Brian Rosen br at brianrosen.net
Wed Aug 10 08:13:02 PDT 2005

I suggest you talk to Henning at Columbia University.

During the aftermath of 9/11, telephone service to Columbia was effectively
out due to congestion.  VoIP service, on the other hand, stayed up.  In New
York, the Internet was much more reliable than the telephone system for a
user.  Generally speaking, that's the reality.  Of course, the telco serving
Columbia would say he did not have a failure.  The customer would say
otherwise, so we have a definition problem.

I make no excuses for improperly engineered IP networks.  It's harder to
build a reliable IP network than an unreliable one.  I make no excuses for
access networks with ridiculously large oversubscription rates on the access
router; if you can't get traffic through the first hop carrier connection,
nothing else matters.  I make no excuses for some VoIP carriers with poorly
designed systems; it's still wild, wild west days, and there are plenty of
providers with little more than string and tin cans.

However, DNS has not failed in, I don't know, something like 15 years.   I
don't think there has been a failure of any Tier 1 Internet provider's core
network in at least 10 years, probably longer.  The access networks are not
as reliable, and we definitely need more work there.  

We're still stuck with power issues on the CPE side.  Geoff says his company
is doing battery backup for the VoIP path.  Good idea.  We need more of

If you had power at your CPE, and your access network provider did a half
way decent job, your Internet service would be much more reliable than your
phone service.  Today, neither of those conditions are common, so that's not
true.  For Columbia, they didn't have a power problem, and their access
network is very good.  IP was much more reliable than PSTN for them.


-----Original Message-----
From: Voipsec-bounces at voipsa.org [mailto:Voipsec-bounces at voipsa.org] On
Behalf Of Dave Pascua
Sent: Tuesday, August 09, 2005 11:15 PM
To: Voipsec at voipsa.org
Subject: Re: [VOIPSEC] RE: TLS as the SIP security mechanism

For true reliability, I'll stick with good old PSTN service.  I can
make phone calls during major blackouts because those expensive telco
techniques were applied.  I highly doubt I can make a successful DNS
lookup during a major blackout, although I can't say that I've


On 8/9/05, Johnston, Alan <alan.johnston at mci.com> wrote:
> For true reliability, I'd suggest looking at the DNS - there haven't been
any outages since around 1984, and all without any of the expensive
techniques used by telcos.  How many nines of reliability is this?

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